The present invention relates to an apparatus for the production of foam materials containing a filler material, in particular foam materials, containing waste foam materials produced from at least two flowable chemical components in addition to the filler material.
In the production of foam materials and their further processing, substantial quantities of waste foam materials are produced. The disposal or re-use of this waste has hitherto presented difficulties. For example, finished blocks of foam material have to be trimmed on all sides because manufacturing conditions necessarily produce defective outer edge zones. The block foam may also be cut, for example for upholstery purposes. Of course, such waste and cuttings can be cut into small pieces to form flock, which can be used as a filling material for cushions, toy animals, and insulation purposes. However, the demand for such material does not nearly correspond to the quantities of waste produced.
It has therefore already been attempted to cut up waste from material in grinders to form flock, moisten it in rotating drums with adhesives and subsequently compress the waste in molds. The moldings thus produced, however, are generally hard and of low quality and value. Waste from cellular plastic skins or compacted bottom zones cannot be used, only pure foam waste can be used in this way.
It has also been attempted to grind waste foam material into powder or granulate particles, mix these particles with a chemical such as polyol, and feed them into a foam production process. The method previously used has been to grind the waste foam material into the finest possible powder and to thicken the polyol with it in a mixing container. This mixture is then fed through pumping and dosing systems to a mixing head. Problems are presented in the dosing pumps because of the highly viscous nature of the mixture. Another particular disadvantage in preparing fine grained or powdery filler materials is the electrostatic charge which is generated, particularly in connection with plastic filler materials. Because of their electrostatic charge, the fillers tend to adhere to and clog pipes.
The object of the present invention therefore is to provide an apparatus with which filler materials, in particular waste foam materials, can be recycled to the production process of foam material, in which the method of addition eliminates the filler materials tendency to clog pipes, and in which the quality of the foam material produced can retain the high standard desired in spite of the filler material.